In this Phase II, randomized double-blind study, the efficacy of topical Polyphenon E in actinic keratosis (AK) patients will be evaluated. Eligibility criteria include female and male subjects over 18 years of age with multiple sites (at least two) of actinic keratosis identified by clinical examination and histologic confirmation of one lesion (Grade 1-3), no history of invasive cancer within five years, not requiring topical medications, and meeting SWOG performance status. Approximately 60 subjects will be enrolled into the study (10-15% drop-out rate), 50 subjects are expected to complete the study. The accrual will take approximately 9 months; approximately 6 subjects will be enrolled each month. Each subject will serve as his/her own control by applying Polyphenon E to one arm and placebo to the other in a blinded manner for 12 weeks or until a documented complete AK regression is achieved. In a subset of 20 patients, biopsies of sun-exposed and non-sun-exposed skin (medial biceps) will also be obtained for SEB analysis. The duration of study is 24 months.